This proposal requests support for an Olympus Fluoroview confocal laser scanning system, to be installed on a microscope which will be purchased from Baker Institute resources. The confocal system and microscope will be in a common core facility, and used for imaging of materials within cells, as well as for such purposes as fluorescence in situ hybridization (FISH) of chromosome spreads. The unit will be available for use by a wide variety of NIH-funded users, with the 10 major users being listed in this application. The requested unit is therefore a versatile machine which is user friendly, and which can be switched between uses, or between microscopes, with minimal set-up or alignment necessary. The ten major users who are participating in this grant hold a total of 13 NIH grants between them. They work in a variety of areas of biological research. Some (Appleton, Baines, Bell, Pearce, Parrish) are working in the areas of virology and parasitology, and the immunity which is directed against those agents. Others are working in the areas of immune responses and fetal development (Antczak), and genetics and metabolic diseases (Acland, Aguirre, Lust, MacLeod). Eight of those investigators (with 10 grants) are in the James A. Baker Institute for Animal Health, which is where the instrument will be housed, while two are in the Department of Microbiology and Immunology at Cornell University. The core microscopy facility at the Baker Institute, where this instrument will be housed, currently contains a Nikon Labphot upright visible light photomicroscope, an Diaphot inverted microscope which is equipped for immunofluorescence, a Nikon TE300 inverted microscope with an Eppendorf 5171 micromanipulation and a 5246 microinjection system, as well as a dissecting microscope. The microscopy facility is currently supervised by the three of the faculty who will be acting as Principle Investigator and advisory committee for this instrument. That committee is comprised of Drs. Colin Parrish, Doug Antczak, Judy Appleton, and Joel Baines. The facility will be maintained on a day-to- day basis by a Baker Institute laboratory technician, Lynne Anguish, who has had extensive experience with use and maintenance of a confocal microscope. Up to 20 percent of her time will be available to maintain the confocal microscope and to help new users learn to use the instrument.